Had a single channel 50w 2x12 (4104?) for a while, nice sounding amp, but needed a lot of maintenance. When it had just been serviced, it sounded sweet as anything, but after a couple of months, the overall output level would drop off slightly, and continue to drop over the period of a few months. Budget for servicing/biasing every 6 months.

With it being a combo, it had both original speakers when I bought it. On the first service, the tech told me that one of the speakers had blown, replaced it with a V30. With the V30 & 1 original speaker (G12-75M?), it sounded fantastic, I tried it with 2 V30's in, and it sounded absolutely dreadful.